A liquid-propellant rocket engine (LRE) with turbine gas afterburning in the combustion chamber of the engine is known. This engine comprises a chamber, two separate turbopump units, booster prepumps mounted on inlet lines, a fuel--liquid hydrogen--pump and an oxidizer--liquid oxygen--pump, a thrust and propellant mixture ratio control system, electric spark ignition units and automatic equipment, ensuring engine starting and shut down ("Liquid-Propellant Rocket Engine Design and Engineering," edited by Prof. G. G. Gakhun, Moscow, Mashinostroenie, 1989, p. 93).
The known engine ensures a high level of reliability parameters and survivability, but a too low liquid hydrogen density (70 kg/m.sup.3) and, as a result thereof, the low density of oxygen-hydrogen propellant substantially limits the use of this propellant composition, and the engine correspondingly, for the first stages of launchers.
The technical solution most similar to the present invention is an LRE with oxidizing turbine gas afterburning in the engine chamber ("Liquid-Propellant Rocket Engine Design and Engineering," edited by Prof. G. G. Gakhun, Moscow, Mashinostroenie, 1989, p. 93).
The known engine comprises a chamber, a turbopump unit with a two-stage fuel pump and a single-stage oxidizer pump, a gas generator, a thrust controller, a throttle for controlling the fuel and oxidizer ratio in the combustion chamber, and automatic equipment for starting and shutting down the engine.
A jet ejector is mounted upstream the oxidizer pump in order to increase the input pressure. This ejector operates on a part of the oxidizer tapped from a high-pressure pipeline downstream the pump. Rocket tank pressurization is carried out using gases produced in autonomous gas generators of the engine.
The known liquid-propellant rocket engine has a relatively simple design, in which neither an ignition system, nor a complicated starting system is used.
But the use of highly toxic components, such as nitrogen tetroxide and unsymmetrical dimethylhydrazine, producing highly toxic products during the combustion process, as a propellant in the known engine does not currently meet the requirements for ecological safety.
Another distinctive feature of the known engine is that it is started using a preliminary stage mode. However, this procedure does not exclude peaks (brief overtemperature and overpressure) in the turbine gas temperature and pressure in the main assemblies while the engine is reaching the nominal mode.
The use of a jet ejector as a booster prepump for the oxidizer does not make it possible to use the engine at low input pressures.
Besides, the use of autonomous gas generators for the rocket tank pressurization, equipped with their own special start/cut-off automatic equipment makes the engine design more complicated.